Aircraft engine apparatus



March 15, 1960 c. H. STOCKDALE 2,928,497

AIRCRAFT ENGINE APPARATUS Filed April 29, 1958 INVENTOR CHARLES H. STOCKDALE BTFM United States Patent AIRCRAFT ENGINE APPARATUS Charles H. Stocirdale, Mission, Kans., assignorto Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application April 29,1958, Serial No. 731,791

8 Claims. (Cl. 183- -62) This invention relates to screens for the air intakes of aircraft engines, more particularly to retractable screens for the air intakes of aviation gas turbine engines, and has for an object to provide improved structures of this type.

Another object is to provide a screen which is re tractable to a position completely out of the air stream and imposes no drag when in the stand-by condition.

A further object is to provide a screen structure having a debris receptacle for collecting debris intercepted by the screen.

In accordance with the invention, there is provided tubular outer and inner shell structure defining an annular air intake opening for an aviation gas turbine engine. The inner shell structure has a forwardly directed open end and an annular foraminous member or screen made of any suitable deformable material, such as wire mesh, is pivotally supported adjacent the open end. The scren is extensible in radially outward direction to a first position across the air intake opening, to intercept debris entrained in the air stream, and is retractable in radially inwardly direction out of the air intake opening to a second or stand by position within the inner shell structure, when desired. A debris receptacle disposed within the inner shell structure is perativelyconnected to the screen with its opening in registry with the central opening in the screen. When the screen is in the first position it assumes a fmstoconical shape. Thus any debris intercepted by the scren is funneled in radially inwardly direction, passes through the central opening therein to the debris receptacle, and is captured thereby.

A suitably faired closure member is further provided for closing the open end of the inner shell structure when the screen is in the retracted position. i

The foregoing and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is an axial sectional view of the forward end portion of an aviation turbojet engine having the invention incorporated therein, the screen structure being shown in the retracted or stand-by position;

Fig. 2 is a view similar to Fig. 1 but with the structure in an intermediate position;

Fig. 3 is a view similar to Fig. 2 but with the screen in the extended position; and

Fig. 4 is a transverse sectional view taken on IV-IV of Fig. 3.

Referring to the drawing in detail, there is shown the forward portion of an aviation turbojet engine equipped with air intake structure 11 embodying the invention. The engine forms no part of the invention. Hence it has not been fully shown. However, as well known in the art, the engine includes the usual components including tubular inner and outer shell structure 12 and 13, respectively, defining an annular air passageway 14 for delivering air to an air compressor 15 of'theaxial flow type. The thus pressurized air is subsequently employed to support combustion of fuel in suitable combustion structure (not shown), thereby generating hot motive gases'which are ejected in rearward direction to impart a propulsive thrust to the engine, after partial expansion in a turbine (not shown) which drives the compressor 15. i

In accordance with theinvention, the air intake structure 11 comprises tubular inner and outer shell structure 16 and 17, respectively, of preferably circular shape, supported in coaxially spaced relation with-each other by a plurality of radial struts 18 and jointly defining an annular air passageway 19 communicating with an annular air intake opening 20. The air intake structure 11 is coaxially supportedby the engine It in any suit: able manner, thereby placing the air passageways 19 and 14 in communication with each other.

The inner shell structure 16 is further provided with a faired closure or nose member 21 for directing incoming air (as indicated by the arrows in Fig. 1) smoothly and with a minimum of turbulence into the air passageway 19 and thence through the passageway 14 to the compressor 15.

The inner shellstructure 1'6 hasa forwardly directed (relative to the direction of flight of the engine 10) open end, as indicated at 22'and the closure member 21 is carried by the actuator rod 23 of a suitable reciprocable power actuator 24 for fore and aft translation, out of and into closingrelation, respectively, with the open end 22. The power actuator 24 is supported in a central position within the inner shell structure by a plurality of struts 26. 7

An annular screen member 27 of unitary construction posed central opening 31 of substantially smaller diameter than the inner shell structure 16 and rearwardly of the opening 31 there is provided a cupshapedreceptacle 32. The receptacle 32 is defined by cylindrical and frusto-conical wall portions 33 and 34, respectively, and has a forwardly directed opening 35 disposed in registry with and of larger diameter than the central opening 31 in the screen member. The receptacle 3-2, hereafter termed a debris trap, is pivotally connected to the rearward portions of the hinge members 30 by an annular array of links 36 and is supported at its rearward end by an open framework or cage 37 which, in turn; is attached to'the actuator rod 38-of a suitable reciprocable power actuator 39. i

Fig. 1 illustrates the air intake structure 11 with thescreen member 27 in the retracted position and disposed 1 within the confines of the inner shell structure '16 and the closure member 21. Thus the air intake opening 20 and the air passageways .19 and 14 are completely open to incoming air. This position is preferably assumed when the aircraft (not shown) powered by the engine 10' is in fiight'at sufficient elevation to substantiallyelimi-- mate the possibility of induction into the engine of harmful solid bolts'or other debris.

Howeveig'durin'g' engine warm-up and/or takeoii'from particles, such as rocks, sand, loose nuts and.

a runway, as wellas approaching and/or landin'gon the runway, the likelihood ,ofentraining loose-debris from, the runway into the air stream and subsequent induction into the engine is so great that it is essential to interceptsuch debris beforeit'caii harmiithegengilie'. 3;; M 1;: Figs. 3 and 4 illustrate ;the air intakesfructure llww h the unitary screen member. 27'in the exteridedipositibil; wherein it extendsicontinuously around'tand f-acfoss th'e' air intake, opening 20 without interruption and efieetiv'e ly" intercepts debrisentrained inthe aincoming air.:' Initlt'e extended position, the screen member isjof substantially frusto-conical' shape and convergent-?inadownstream d if rection relative to air flow. Hence, anydebris iintei'cepted thereby is quickly funneled by its own momentum in-"radially inw'a'rdldirectio'n andejected'jthrou'gh the screen" opening 31 info: the'debris tra'p 32;wherein' it is ositively retained, until i-ernov'al ithei'efrom diirin'g to engine inspecito'n 'or servicing: procedulr'ee been -When it is desired to condition the air intake str'u'ctu e for removal of debris from the incqmingairstrearn, the power actuator 24 is first energized byZany suitable ine' ins (not shown) in a directionto extend'its ac'tuator ro'dz2:3, thereby axially translating the 'closureimembei- '21 forwardly or to the 'left. At the end of its forward travel, the rearward edge of the closure 'rnenib'er 21 and the forward edge of the inner'shell structurejointlydefine an annular opening 41 permitting egress of the sc'reen member. This intermediate positioiilis b'est sh wan Fig.2.

I The power actuator '39 is then energised by anysuitable means (not shown) in a direction to extend'its' actuator rod 38 and translate the cage 37 in foi'waril tion. Referring to Fig. 3, it will :bese enthtat;" atliea cage 37' istranslated in forward direction, thefdebris trap and links.37 are also urged forwardly, rotating thej ribs 29 of the screen member in radially outwardly dii ection about the hinge members 3!) from their 'parall'el'positions to'their mutually divergent positions.'- The ribs '29 are thus projected through the opening 41 into abutment with the inner periphery of the outer shell structure" and'exf tend the screen across the air intakeopening. il r'r this' position, the screen member assumes a frusto-conicalor funnel shape with its rearward opening 31 of considerably less diameter than its forward opening. if,

With the screen member in the positionshown in Fig; 3,: debris is intercepted thereby and funneled inwardly, passing through the rearwardopeninginto the debris ,trap 32." Accordingly, clogging of the Screen nateritiljZS is obviated even after asevere encounter debris and air pressure drop-across the screen may'beconsistently maintained within reasonable limits; I e 1;.

I Such pressure drop inherently reduces theioperating efficiency of the engine 10. Accordingly, during flight at reasonably debris-clear altitudes the air intake strncture is positioned as shown in Fig; 1.' Torever t to this" position from the. position shown in Fig. 3 thesequence of operations outlinedabove is merely reversed. 'jfl'hat is, the actuator 39 is firstretracted,,therebyretracting the screen member 27 and deforming the lattertothe substantially cylindrical shape shown in Fig. grmen power actuator 24 isretractedthereby rearwany, ran i lating the closure member 2 1 into'abutm 'nt inner shell structure :16.

It will now be seenthattheinventionipro improved air intake structur'ejforjan 'airc ft thereof even after a severe encounte asap,

i With the screeniii the retracted position, the air intake structure presents smooth surface A contours to the air stream flowing therethrough, thereby permitting performance of the structure'at optimum efficiency.

While the invention has been shown in but one form, it will be obvious to those skilled'in theart that it is not What is Eliiifitedisi l lnani ircraftengine having tubular outer and inner sh structure de 'gfanannular air intake opening, an annular foraminous member, means for movably supporting said fgraminousrnernher on said inner shell strucspirit thereof.

ture, said foramlnous iiiember being extensible in radially outwardly directign to a first position; agross said intake opening and retractable'in radially inwardly direction to a second position within said inner shell structure, said fora miuou s member assuming a substantially frusto-conicalishape convergent i ii downstream direction relative to air flow through said intake opening, whereby debris intercepted thereby is funneled toward "said inner shell structure, and actuator ineans for moving said forammous v member to said first and said second position.- v

* "2. In an aircraft engine havinghaving tubular outer and innershell structure defining an annular air intake opening; an annular foraminous member having a pcripheral edge portion defining a central opening, said inner shell structurehaving a central'opening, means for pivotally supporting said foratninousrnember in a central position adjacent the opening in said inner shell structure, the opening in'said inner shell structure being in registry with the opening in said foraminous member,

said foraniinous-rnember being extensible in radially out wardly direction through'theopening in said tuner shell structureto a'-first position across's'aid intake opening andjretractable in radially inwardly directionthrough the opening in said inner shell structure to a second position withinthe periphery of said inner shell structure, and

actuator" means for moving said foraminous-m ember to said first and said second position.

3. In anaircraft engine havi shell structure defining an annular air intake opening,

an annularscreen member deformable from cylindrical shape'to frusto-conical shape, meansprovided on said 4. In an aircraft engine'jhaving tubular. outer and inner sh el l structuredisposed in coaxial alignment and defining an annular air intake opening, said inner. shell structure.

havingfa forwardlydirected open end, anannular deformable screen member, means for pivotally supporting v.said screen member in.,a central position adjacent the open end of: said inner shell structure, said screen mem: ber being adivergible v in radially outwardly direction through said open end of said inner shell structure to al firstposition across said intake opening and, convergibl'e in radially inwardly direction through saidppen end to a t sceond po sitio n within saidinner shell structure, "actuator means for moving said screen member to said first and said second .position, and r novably supported fairing memberfor closing the open end of said inner shell structure when said screen member is disposed in said ,secondposition. a

annularffora r'ninous member having a peripheral marginal ng tubular outer and inner l i eirs s s teh hs ib l nii di n sh'ellstructuredefining an annular ainintake'opening, an.

structure, a wall Structure defining a debris receptacle having an entrance opening in registry with the central opening in said foraminous member, said foraminous member being extensible in radially outwardly direction to a first position across said intake opening and retractable in radially inwardly direction to a second position within said inner shell structure, and actuator means for moving said foraminous member to said first and said second position.

6. In an aircraft engine having tubular outer and inner shell structure defining an annular air intake opening, an annular screen member having a rear peripheral portion defining a central opening and deformable from a sub stantially cylindrical shape to frusto-conical shape, means for pivotally supporting said screen member on said inner shell structure, wall structure defining a debris receptacle having an entrance opening in registry with the central opening in said foraminous member, said screen member being extensible in radially outwardly direction to a first position across said intake opening and retractable in radially inwardly direction to a second position within said inner shell structure, first actuator means for moving said screen member to said first and said second position, a movably supported fairing member disposed forwardly of and in coaxial alignment with said inner shell structure, and second actuator means for moving said fairing member into and out of abutment with said inner shell structure, said screen member assuming a said frusto-conical shape in said first position and said cylindrical shape in said second position.

7. In an aircraft engine having tubular outer and inner shell structure defining an annular air intake opening, a unitary annular foraminous member having a central opening, means provided on said inner shell structure for pivotally supporting said foraminous member, a translatable wall structure defining a debris receptacle having an entrance opening in registry with the central opening in said foraminous member, said debris receptacle being disposed within said inner shell structure, said foraminous member being extensible in radially outwardly direction to a first position across said intake opening and retrace table in radially inwardly direction to a second position within said inner shell structure, means operatively connecting said debris receptacle to said foraminous member, and actuator means for'translating said debris receptacle, said debris receptacle being movable in one direction to move said foraminous member to said first position and in the opposite direction to move said foraminous member to said second position.

'8. In an aircraft engine having tubular outer and inner shell structure defining an annular air intake opening, said inner shell having an open end, a faired closure member for closing said open end, a unitary annular screen member having a central opening, means for pivotally supporting said screen member adjacent the open, 7

end of said inner shell structure, a movably, supported wall structure defining a debris receptacle having an entrance opening in registry with the central opening in said screen member, said screen member being extensible in radially outwardly direction through the open end of said inner shell structure to a first position across said intake opening and retractable in radially inwardly direction through said open end to a second position within said inner shell structure, means operatively connecting said debris receptacle to said screen member, first actu ator means for moving said screen member to said first and said second position, and second actuator means for moving said closure member into abutment with said' inner shell structure when said screen member is in said second position and out of abutment therewith to permit movement of said screen member to'said first position.

No references cited. 

